GB1583235A - Process for preparing bead polymers - Google Patents

Description

PATENT SPECIFICATION ( 11) 1 583 235

k ( 21) Application No 250/78 ( 22) Filed 4 Jan 1978 C ( 31) Convention Application No 52/000 289 ( 32) Filed 5 Jan 1977 in 00 ( 33) Japan (JP) i ( 44) Complete Specification published 21 Jan 1981 rs ( 51) INT CL 3 CO 8 F 20/34 ( 52) Index at acceptance C 3 P JM C 3 W 211 C 325 C C 3 Y B 186 F 260 ( 72) Inventors OSAMU KAMADA, KENZOH WATANABE and SHIGERU SAWAYAMA ( 54) PROCESS FOR PREPARING BEAD POLYMERS ( 71) We, MITSUBISHI CHEMICAL INDUSTRIES LIMITED, a company organised under the laws of Japan, of No 5-2, Marunouchi 2-chome, Chiyoda-ku, Tokyo, Japan, and KYORITSU YUKI COMPANY LIMITED, a company organised under the laws of Japan, of No 13-15, Ginza 7-chome, Chuoku, Tokyo, Japan, do hereby declare the invention, for which we pray that a patent 5 may be granted to us, and the method by which it is to be performed, to be particularly

described in and by the following statement:-

The present invention relates to a process for preparing a water-soluble cationic bead polymer.

Water-soluble high molecular weight polymers which are obtained by poly 10 merising monomers such as neutralized salts or quatemary compounds of dialkyl aminoalkyl (meth)acrylates have important uses as, for example, flocculating agents, soil conditioners, drainages, retention aids, sizing agents and in treatment of fibers.

Recently, such polymers have been used in large amounts as dehydration accelerators for surplus sludges formed in activated sewage treatment of faeces, and in 15 sewage treatment plants and chemical and food processing plants They have, accordingly, acquired a degree of importance as waste water treating agents.

If a water-soluble cationic polymer is used as a flocculating agent, the higher its molecular weight, the greater its effectiveness It has been proposed to produce water soluble polymers by polymerizing a monomer such as a neutralized salt or a 20 quatemary ammonium salt of dialkylaminoalkyl (meth)acrylate by methods in which the polymers, for example polyacrylamide, are prepared by the usual free radical mechanism, for instance aqueous solution polymerizations, precipitation polymerization and suspension polymerizations.

In order to obtain high molecular weight polymers by aqueous solution poly 25 merization, the polymerization is carried out with a monomer concentration of at least % by weight; the products are gummeous and contain water Since such nolvmers require a long time for dissolution and are also difficult to transport, they are usually powdered by grinding and drying Also, when carrying out this method there is a tendency for the molecular weight to decrease to a remarkable extent due to the 30 difficulty of stirring the reaction mixture during polymerization which makes the removal of the reaction heat more difficult, and results in non-uniform products.

When carrying out precipitation polymerization uniform and powdery polymers are easily obtained; however, if a solvent having high polarity and capable of dissolving neutralized salts and quaternary ammonium salt of dialkylaminoalkyl (meth) acrylates 35 is selected, it is difficult, using such a solvent, to obtain high molecular weight polymers due to a significant chain transfer action of solvent during polymerization and the polymer products tend to be in the form of finely divided powder.

On the other hand, when using suspension polymerization high molecular weight polymers in powder form are readily obtained due to the ease with which reaction 40 heat can be removed Accordingly to a conventional method, for example, as disclosed in British Patent 841127 or U S Patent No 3,211,708, an aqueous solution of monomer is polymerized in an inert dispersion medium using a nonionic emulsifier to give a water-in-oil or oil-in-water type emulsion.

When this latter method is applied to the polymerization of monomers comprising neutralized salts and quaternary ammonium salts of dialkylaminoalkyl (meth)acrylates, it is difficult to form emulsions owing to the salting-out effect of these salts Even if the emulsions are formed under appropriate conditions, for example, by using a very low concentration of the aqueous monomer solution, there will be a 5 tendency to be obtained polymers in the form of a very fine powder after polymerizing and drying These very finely powdered water-soluble polymers exhibit a very slow rate of dissolution since they bring in air bubbles upon dissolving in water.

Moreover, these polymers are scattered as dust during the dissolving operation and the working atmosphere is polluted In order to obtain by suspension polymerization 10 products which are not finely powdered, an aqueous solution of monomer should be polymerized in the state of dispersed drops using a suitable dispersion stabilizer but not forming an emulsion with an emulsifier.

A method for polymerizing an aqueous solution of water-soluble vinyl monomer is by suspending it as droplets is disclosed in Japanese Patent Publication No 9,656/ 15 1967 According to this previously proposed method, the polymerization is carried out in a dispersing medium based on a halogenated olefin in which an oleophilic cellulose derivative is dissolved and it is necessary to adjust the specific gravity of the dispersing medium by admixing hydrocarbon, so that it is equal to or more or less higher than the specific gravity of the aqueous monomer solution There are found, 20 in this last mentioned Publication, examples of polymerization in which from 30 to % by weight aqueous solutions of sodium acrylate and sodium acrylateacrylamide, sodium methacrylate-methacrylamide and sodium acrylate-vinyl pyrrolidone mixtures are used It is impossible to polymerize these monomers at a higher concentration because they are not sufficiently soluble in water Accordingly, although the products 25 obtained are water-containing, spherical, gelatinous substances free from fine polymers, and it is difficult to convert them into solid product by an industrial process.

A method using a cellulose derivative as a dispersion stabilizer has been proposed in Japanese Patent Publication No 40,304/1962; the polymerization is carried out by suspending, in an aliphatic or aromatic nonpolar solvent, a watersoluble cellulose 30 compound, which is insoluble in the dispersing medium, and adding an aqueous solution of vinyl monomer to the suspension This method has, however, a tendency to give finely powdered products.

This invention is predicated in our observations that it is apparently possible to polymerize neutralized salts and quaternary ammonium salts of dialkyl amino alkyl 35 (meth)'acrylate at any concentration in an aqueous solution, especially, using a highly concentrated aqueous solution of the monomers, if a specific dispersion stabilizer is used in combination with or without a specific suspension medium Accordingly, the present invention provides a process for preparing a watersoluble bead polymer by dispersing dropwise an aqueous solution of a water-soluble 40 vinyl monomer in a dispersing medium and polymerizing the monomer in the presence of a dispersion stabilizer, wherein (A) a compound of the general formula I RI R 2 CH 2 = C -0 Y NO R 3 xe 0 R 4 (I) wherein R' is hydrogen or methyl, R 2 and R 3 may be the same or different and each is linear or branched alkyl of from 1 to 4 carbon atoms, R 4 is hydrogen or 45 linear or branched alkyl of from 1 to 8 carbon atoms, hydroxyl alkyl of from 1 to 4 carbon atoms or benzyl, Y is alkylene or hydroxyl alkylene each of from 2 to 4 carbon atoms, and X is an anion, or (B) a mixture of the compound of the formula I and a water-soluble vinyl monomer copolymerizable with the compound (I) is used as the water-soluble vinyl monomer; and a cellulose ester or cellulose ether insoluble S O in water but soluble in the dispersing medium is used as the dispersion stabilizer.

Monomers of the formula I include salts of dialkylaminoalkyl acrylates or dialkylaminoalkyl acrylates or dialkylaminoalkyl methacrylates of the general formula II RI R 2 CH 2-C-C-O-Y-N 0 (I) 1,583,235 wherein R', R 2, R' and Y have the same meanings as in the formula I, with inorganic acids, carboxylic acids and sulfonic acids These salts are referred to herein as "neutralized salts " Examples of the compounds of the formula II are specifically dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethyl 5 aminoethyl methacrylate, dibutylaminoethyl acrylate, dibutyl aminoethyl methacrylate, methylethylaminoethyl acrylate and dimethylamino-2-hydroxypropyl methacrylate.

The inorganic acids are, for example, hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, the carboxylic acids are, for example, acetic acid and propionic acid, and the sulfonic acids are, for example, benzene sulfonic acid and tosyl sulfonic acid 10 The compounds of the formula I also include quaternary ammonium salts which are obtained by reacting the acrylates and methacrylates of the formula II, with quaternizing agent such as alkyl halides, aralkyl halides and dialkyl sulfates Examples of the quaternary ammonium compounds are /,-methacryloyloxyethyl trimethyl ammonium chloride,,B-methacryloyloxyethyl trimethyl ammonium methyl sulfate, 15 fl-methacryloyloxyethyl dimethyl-ethyl ammonium bromide,,methacryloyloxyethyl dimethyl-ethyl ammonium monoethyl sulfate, /-methacryloyloxyethyl dimethylbenzyl ammonium chloride,,B-acryloyloxyethyl trimethyl ammonium chloride,,,acryloyloxyethyl triethyl ammonium bromide and 2-hydroxy-3-methacryloyloxypropyl trimethyl ammonium chloride 20 Water-soluble high-molecular weight cationic polymers which may be produced in the practice of the invention include homopolymer of the compounds of the formula I as well as copolymers of the compounds (I) which is contained at least mole% and other water-soluble vinyl monomers copolymerizable with the compound (I) For example, acrylamide and methacrylamide are used as the other water-soluble 25 vinyl monomer copolymerizable with the compounds (I).

Cellulose esters or cellulose ethers used as the dispersion stabilizer are, for example, water-insoluble ones such as cellulose acetate, cellulose propionate, cellulose butvrate, cellulose acetate butyrate, cellulose acetate phthalate, ethyl cellulose, ethyl hydroxyethyl cellulose and benzyl cellulose, and it is preferred to use cellulose acetate butyrate, 30 ethyl cellulose and ethyl hydroxyethyl cellulose As the dispersing medium, organic liquids are used which are substantially immiscible with the aqueous monomer solutions used and are inert under the polymerization conditions.

Some water-insoluble cellulose esters and ethers exhibit different properties in a variety of solvents, for example, as follows: 35 1) Soluble, solution clear of haze and free from gels.

2) Soluble, solution hazy and free from gels.

3) Soluble, solution of granular nature due to presence of gels.

4) Completely gelatinized.

5) Swollen, or incompletely gelatinized 40 6) Insoluble not swollen.

Compounds having the properties of from 1) to 3) dissolve the cellulose esters or ethers, and compounds having the properties of from 4) to 6) do not dissolve cellulose ester or ethers In order to attain a good dispersion stability, it is preferred to use as the dispersing medium compounds having the property 3) or compounds 45 which have properties of 4) and 5) at room temperature but which can dissolve the cellulose esters or ethers at an elevated temperature at which the polymerization is carried out However, it is in general not easy to find out the combination of the dispersing medium with the dispersion stabilizer exhibiting the above preferred properties Thus a condition under which the dispersion is generally of good stability 50 may be advantageously obtained in such a manner that a compound capable of gelatinizing or swelling the dispersion stabilizer, a compound having the properties 4) or 5), is added gradually to a solution in which the dispersion stabilizer is dissolved, a limit point at which the dispersion stabilizer is insolubilized is determined and a mixture of compounds of a mixing ratio close to the above limit point is used 55 as the dispersed medium If a compound with property 6) is added to a compound with properties 1), 2) or 3), the stability of the dispersion is remarkably decreased.

The properties of water-insoluble cellulose esters and ethers in a variety of solvents are influenced to a great extent by their substituents and the degree of substitution of anhydrous glucose units, and can be roughly classified as follows: 60 i) soluble in polar compounds such as esters, ketones, alkyl halides, nitroalkanes, alcohols and ethers but insoluble in compounds such as aromatic hydrocarbons and halogenated aromatic hydrocarbons.

ii) soluble in polar compounds as mentioned in i) aromatic hydrocarbons and 1,583,235 halogenated aromatic hydrocarbons but insoluble in cycloaliphatic hydrocarbons.

iii) soluble also in cycloaliphatic hydrocarbons but insoluble in aliphatic hydrocarbons.

lIl First, cellulose esters and ethers having the properties of i) will be dis 5 cussed These cellulose esters and ethers include, for example cellulose acetate, cellulose acetate butyrate, ethyl cellulose containing from 43 to 46 % by weight of ethoxy groups and cellulose acetate phthalate As solvents which gelatinize or swell these cellulose derivatives, it is preferable to use aromatic hydrocarbons and halogenated aromatic hydrocarbons Also the following esters, ketones and alkyl halides are preferably used 10 as compounds dissolving these cellulose derivatives.

Esters of aliphatic carboxylic acids of from 1 fo 8 carbon atoms or aromatic carboxylic acid of from 7 to 8 carbon atoms with alkanol or alkoxy alkanol, each alkanol of from 1 to 8 carbon atoms These esters are in particular, for example, methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, nbutyl acetate, isobutyl acetate, t-butyl acetate, phenyl acetate, benzyl acetate, methoxyethyl acetate, butoxyethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, butyl butyrate, methyl valerate, methyl caproate, methyl caprylate, methyl benzoate, ethyl benzoate, n-butyl benzoate, dimethyl phthalate, diethyl phthalate and dibutyl phthalate.

Esters of aliphatic carboxylic acids with alkanol or alkoxy alkanol are preferable 20 amongst the above esters.

Ketones include aliphatic ketones of from 3 to 10 total carbon atoms or aromatic ketones of from 8 to 13 total carbon atoms For example, these ketones are in particular acetone, methyl ethyl ketone (MEK), methyl n-propyl ketone, diethyl ketone, cyclopentanone, methyl butyl ketone, methyl isobutyl ketone (MIBK), cyclohexanone, 25 methyl amyl ketone, dipropyl ketone, hexyl methyl ketone, acetophenone and benzophenone.

Alkyl halides include alkyl halides of from 1 to 6 carbon atoms, preferably of from 2 to 4 carbon atoms Especially preferable alkyl halides are those which have from 2 to 4 carbon atoms and the each of two adjacent carbon atoms are substituted 30 by at least one halogen, respectively Examples of these alkyl halides are 1,2-dichloroethane; 1,1,2-trichloroethane; 1,1,2,2-tetrachloroethane; pentachloroethane, 1,2dichloropropane; 1,2-dibromomethane; 1,1,2-tribromoethane; 1,2dibromopropane; and 1,2-dibromobutane.

Other alkyl halides such as methylene chloride, chloroform and carbon tetra 35 chloride may not be used in some cases as a dispersing medium for the suspension polymerization since they are of lower boiling point and further may dissolve the monomers of the formula I Also, alkyl halides which are substituted at only one of the adjacent carbon atoms by halogen may require certain measures to be taken to prevent lumping, for example, by increasing the rate of polymerization since these 40 alkyl halides may dissolve only low-molecular weight cellulose esters and ethers and therefore the dispersion stability during polymerization may be reduced.

As compounds which do not dissolve the dispersion stabilizers and are to be added to the above compounds dissolving the stabilizers for the pnurnose of improving the disnersion stability, solvents which gelatinize as well as swell the stabilizers may 45 be used, but aromatic hydrocarbons and halogenated aromatic hydrocarbons each of from 6 to 8 carbon atoms are especially preferred, for example, benzene, toluene, xvlene, ethylbenzene, monochlorobenzene, dichlorobenzene, monobromobenzene and dibromobenzene The aromatic hydrocarbons or halogenated aromatic hydrocarbons to be added to the compounds dissolving the dispersion stabilizers are advantageously 50 used in an amount up to an uppermost limit by which the stabilizers are not insolubilized In order to attain the optimum conditions of dispersion, a ratio, by weight, of the compounds dissolving the dispersion stabilizers to the aromatic hydrocarbons or halogenated aromatic hydrocarbons may be defined within the following range:

1 n > X 2 N n, preferably 55 1 n > X 2 > n 2 wherein X stands for a ratio, by weight, of the aromatic hydrocarbons or halogenated 1,583,235 aromatic hydrocarbons to the compounds which easily dissolve the dispersion stabilizers and N stands for a value of X at a time when the stabilizers start to become insoluble In this case, insolubilization means the state where the dispersion stabilizers can be observed by the naked eye to become insoluble If X is equal to or larger than n, the dispersion stabilizers will not be solubilized, on the other hand, if X is 5 less than 1/3 n, the dispersion stability will be insufficient Cellulose acetate butyrate is the most preferable among the cellulose derivatives having the properties of i) It is necessary to use alkyl halide in excess to aromatic hydrocarbons So it is preferable to use esters or ketones among above dispersing media.

lIIl Next, cellulose esters and ethers having the properties of ii) will be 10 discussed These cellulose derivatives include ethyl cellulose which contains from 47 to 50 % by weight of ethoxy groups Although such ethyl cellulose containing of from 47 to 50 % by weight of ethoxy groups are insoluble in cycloaliphatic hydrocarbons at room temperature, they are soluble in the latter under a heated condition to give is a dispersion system of good stability Consequentially, the polymerization may be 15 carried out at a temperature of 550 C or higher using the ethyl cellulose in a well dispersed state of the aqueous monomer solution.

If such ethyl cellulose is used, the compounds dissolving the cellulose derivatives may suitably be combined for the purpose of lowering the temperature at which a good dispersion stability is obtained rather than the purpose of improving the dis 20 persion stability Examples for these compounds dissolving the ethyl cellulose are aromatic hydrocarbons, halogenated hydrocarbons, esters, ketones, alkyl halides, ethers and alcohols Cycloaliphatic hydrocarbons to be used as the dispersing medium in this case include cycloaliphatic or alkyl-substituted cycloaliphatic hydrocarbons each of from 5 to 10 carbon atoms, for example, cyclopentane, cyclohexane, cycloheptane, 25 methyl cyclohexane, cyclooctane and decaline.

Although it is also possible to use a single dispersing medium from the above aromatic or halogenated aromatic hydrocarbons each of from 6 to 8 carbon atoms, it is generally necessary in this case to increase the rate of polymerization for obtaining the bead polymer of uniform particle size since the dispersion stability is usually 30 somewhat insufficient If the cycloaliphatic hydrocarbons are used in combination with the aromatic or halogenated aromatic hydrocarbons, it may be advantageous to add the latter in an amount, by weight, of up to 4 times, and preferably, up to 2 times, based on the former.

If a mixture of the cycloaliphatic hydrocarbon and esters, ketones or alkyl halides 35 is used, the latter may advantageously be added in an amount, by weight, of up to 2 times, and preferably up to 1 5 times, that of the former In this case, besides the alkyl halides which dissolve compounds such as cellulose acetate, butyrate as described in the above I, for example, methylene chloride and carbon tetrachloride may also be used 40 Moreover, if the cycloaliphatic hydrocarbons are mixed with ethers or alcohol, the latter may advantageously be used in an amount, by weight, of up to 0 3 times, preferably up to 0 2 times the former.

Ethers which may be mixed with the cycloaliphatic hydrocarbons include linear and cyclic ethers each containing from 4 to 8 total carbon atoms, for example, di-n-propyl 45 ether, di-n-butyl ether, tetrahydrofuran, dioxane, diethylene glycol and dimethyl ether.

Alcohols which may be mixed with the cycloaliphatic hydrocarbons include alkanols and alkoxy alkanols each containing from 2 to 8 carbon atoms, for example, ethanol, n-propanol, n-butanol, ri-octanol, methoxyethanol, ethoxyethanol, butoxy 50 ethanol and diethylene glycol monomethyl ether 5 Compounds other than those described above are not suited for solvents for the ethyl cellulose.

lIIIl An example for the cellulose esters or cellulose ethers having the properties of iii) is ethyl hydroxyethyl cellulose, Ethyl hydroxyethyl cellulose mixed cellulose esters can be obtained by hydroxy 55 ethylation and ethylation of alkali cellulose with ethylene oxide and ethyl chloride, respectively, and it is soluble in solvents which dissolve ethyl cellulose as well as in cycloaliphatic hydrocarbons, and is insoluble in saturated aliphatic hydrocarbons Ethyl hydroxyethyl cellulose can, however, be dissolved in saturated aliphatic hydrocarbons having a boiling point in the range of from 35 to 180 C, under heating, and accord 60 ingly if such a saturated aliphatic hydrocarbon is used alone, a dispersion system having a good dispersion stability will be formed by dispersing the aqueous monomer solution at a temperature of 550 C or higher In this case, the heating may be carried out under pressure, if necessary.

1,583,235 As the boiling point of the saturated aliphatic hydrocarbons contemplated for use as the dispersing medium becomes higher, they also require a higher temperature for dissolving ethyl hydroxyethyl cellulose, and since those with a boiling point higher than 180 'C can dissolve the cellulose only with difficulty, even at 10 CC or more, the saturated aliphatic hydrocarbons having a boiling point in the range of from 5 to 180 WC are most advantageous if used alone On the other hand, if solvents which dissolve ethyl hydroxyethyl cellulose are admixed, it is also possible to use the saturated aliphatic hydrocarbons having a boiling point in the range of from to 400 C as the dispersing medium and may give a very stable dispersion system at room temperature 10 Solvents capable of dissolving ethyl hydroxvethyl cellulose include esters, ketones, alkyl halides, ethers, alcohols, aromatic hydrocarbons and halogenated aromatic hydrocarbons, for example, those having been mentioned hereinbefore in particular as the solvents capable of dissolving ethyl cellulose, as well as cycloaliphatic hydrocarbons, for example, those having also been mentioned hereinbefore in particular as suitable 15 solvents for ethyl cellulose under heating.

In cases where the above solvents are used together with the saturated aliphatic hydrocarbons as the dispersing medium, the solvents are advantageously added in the following amounts: Each of the esters, ketones, alkyl halides, ethers and alcohols is used in an amount of up to 0 3 times, each of the aromatic and halogenated aromatic 20 hydrocarbons up to 1 times, and each of the cycloaliphatic hydrocarbons up to 10 times, the weight of the saturated aliphatic hydrocarbons, respectively.

The saturated aliphatic hydrocarbons having boiling points in the range of from to 1800 C which may be used as the dispersing medium under heating for dissolving ethyl hydroxyethyl cellulose or together with other solvents includes linear or branched 25 saturated hydrocarbons, for example, pentane, hexane, heptane, octane, nonane and decane The saturated linear hydrocarbons, which are used as the dispersing medium by mixing them with other compounds capable of dissolving ethyl hydroxyethyl cellulose, may contain, for example, undecane, dodecane, tetradecane, octadecane, tetracosane or pentatriacontane 30 From the above description, it will be appreciated that any suitable petroleum fraction containing the saturated aliphatic hydrocarbons having a boiling point in the range of from 35 to 180 C may also be used in a similar manner as the above saturated hydrocarbons A petroleum fraction containing mostly saturated aliphatic hydrocarbons exhibits properties similar to those of saturated aliphatic hydrocarbons alone, and a 35 petroleum fraction containing aromatic and cycloaliphatic hydrocarbons exhibits properties similar to those of a dispersing medium which is obtained by mixing these aromatic and cycloaliphatic hydrocarbons with the saturated aliphatic saturated hydrocarbons.

Examples of petroleum fractions which may be used as the dispersing medium are petroleum ether, ligroin, kerosine and liquid paraffin 40 The above description has been primarily concerned with setting out directions for the preferred use of respective dispersing media suited for combined use with respective dispersion stabilizers, for example cellulose acetate butyrate, ethyl cellulose and ethylhydroxyethyl cellulose Although these and other cellulose esters and ethers may undergo changes in their behavior against solvents depending upon the degree 45 of substitution in the anhydrous glucose unit, it will be understood that dispersion stabilizers other than those which have particularly been described hereinbefore may also be used and give stable, dispersed, polymerization systems, if the dispersing medium gelatinizing or swelling these dispersion stabilizers is combined with "solvents capable of dissolving the cellulose derivatives used as the dispersion stabilizer" or 50 "solvents capable of dissolving the dispersion stabilizer under heating " The amount of the dispersion stabilizers to be added is generally from 0 05 to % by weight, preferably from 0 5 to 5 % by weight, based on the dispersing medium If it is smaller than 0 05 % by weight, the dispersing power may be insufficient, while an amount in excess of 10 % by weight may give products of 55 very fine powder and further make the dispersion system more viscous to cause difficulties upon separation of the products.

The dispersing medium may be used from 0 5 to 10 times, preferably from 1 to 5 times, based on the weight of aqueous monomer solution containing the compound of formula I 60 In the practice of the present invention there is no restriction in the sequence of addition of the dispersion stabilizer, dispersing medium, aqueous monomer solution and a radical polymerization initiator However, in order to obtain products with uniform particle size, the following procedure may be advantageously used; after 1,583,235 7 1,583,235 7 removing oxygen by introducing nitrogen into the dispersing medium in which the dispersion stabilizer has been dissolved, the aqueous monomer solution containing the radical polymerization initiator, from which oxygen has similarly been removed, is added into the dispersing medium and then the mixture is stirred to disperse the aqueous monomer solution in the medium and the temperature is elevated to the range 5 appropriate for the initiation polymerization.

Although conventional radical polymerization initiators such as peroxides and azo compounds may be used as the initiator, water-soluble polymerization initiators are especially preferred, examples being peroxides such as ammonium persulfate, potassium persulfate, peracetic acid and hydrogen peroxide, and azo compounds such as 2,2 ' 10 azo-bis-2-amidinopropane hydrochloride, 4,4 '-azo-bis-cyanopentanoic acid If the peroxides are used as the initiator, it is also possible, as occasion demands, to carry out the redox polymerization in the presence of a reducing agent such as sodium methabisulfite, sodium sulfite or ferrous chloride.

Although the polymerization may be carried out at any suitable temperature of isfrom e g 40 WC to a temperature at which the dispersing medium boils, in order to obtain high-molecular weight polymers a temperature of from 50 to 700 C is preferred.

Any stirring means may be used, and the reaction mixture is usually stirred in such a manner that the drops of the aqueous monomer solution formed in the dispersing medium have a desired particle size Particle sizes of the bead polymers 20 obtained depend on the size of drops Although the bead polymers may have any particle size, it is in general desirable that they are in the range of from 0 05 to 1 mm and preferably from 0 1 to 1 mm.

The monomer concentration in the aqueous solution of the compound of the formula I or a mixture of the compound (I) and an other water-soluble vinyl 25 monomer copolymerizable with the compound (I) may vary in the range of from to 90 % by weight.

If the dispersion stabilizer and the dispersion medium are appropriately selected, it is possible to carry out the polymerization using an aqueous monomer solution containing compound (II) in an amount of from 50 to 100 mole%, based on the total 30 of the water-soluble monomers, and vinyl monomer in an amount of from 60 to 90 % by weight, based on the aqueous solution Thus the high-molecular weight products may be obtained with good productivity, since the high concentrations of the monomer solution can be used Moreover, polymerization with an aqueous solution whose monomer concentration of from 60 to 75 % by weight requires only a brief dehydration 35 period to yield the solid products; when the monomer concentration is from 75 to % by weight, the solid product may be obtained without the need for any dehydration step However, conventional dehydration methods will usually be applied to such water-containing polymers, for example an extraction dehydration, for example with methanol or acetone On the other hand, when compound I amounts to 5 40 mole% to 50 mole%, based on the sum of the water-soluble vinyl monomers, it is difficult to polymerize the aqueous monomer solution at higher monomer concentration, since the products formed tend to insolubilize in water.

If an aqueous solution with a monomer concentration of 10 % by weight to 60 % by weight is used, a water-soluble high-molecular weight polymer may be 45 obtained However, these polymers are obtained in the form of a highly viscous, gelatinous and water-containing spherical material Although such products can be processed to form the bead solids by dehydration on a laboratory scale, for example "by dispersing the products in 100 times its own volume of acetone" or "by drying the product being spreaded as a flat layer", it is extremely difficult to dehydrate or 50 dry them to give the bead products by industrial methods.

An advantageous method involves the use of azeotropic distillation of a dispersing medium-water azeotrope of water-containing products obtained by the abovementioned suspension polymerization A method of suspension polymerization has been proposed in which an aqueous solution of a water-soluble monomer is dispersed in a hydrophobic 55 dispersing medium under the use of a nonionic emulsifier to form water-inoil type or oil-in-water type emulsion If such method is applied to the polymerization of the aqueous water-soluble monomer solution containing from 5 to 50 mole% of compound (I), and then after polymerization the suspension is subjected to azeotrope distillation, lumpy polymer material is obtained in many cases 60 However generally speaking, even if the suspensions of the water-soluble polymers which are formed by polymerization operations according to the present invention by using the dispersion stabilizer and the dispersing medium are subjected to a dispersion medium-water azeotropic distillation under heating, the particles of the 8 1,583,235 8 water-soluble polymers do not adhere one to another Thus, it is usually possible to carry out the polymerization step azeotropic distillation dehydration step as a continuous operation, the dispersion stabilizer displaying its effect in each step Accordingly the solid bead polymer products can be obtained by using from 10 to 60 % by weight of the aqueous solutions containing the compound I and other monomer 5 as the starting material.

In order to effect dehydration by azeotropic distillation, the dispersing medium must be a compound forming an azeotrope with water when the medium is a single component However, if the dispersing medium is a multi-component system, it is sufficient that at least one component of the system may form an azeotrope with 10 water In the case where the dispersing medium is a mixed solvent, an amount corresponding to the medium distilled should be supplemented continuously during the azeotropic distillation in order to maintain good dispersion stability by virtue of the existence of medium of constant composition.

If the dispersing medium is almost immiscible with water, the dispersing medium 15 may be separated from the distilled azeotrope and recycled to maintain the composition of the medium constant Carrying out the dehydration by azeotropic distillation until the water content of the polymers is as low as 20 % and preferably down to %, the polymers obtained will be solid products.

From the above description, it will be appreciated that it is possible to obtain 20 solid bead polymers by separating off the dispersing medium from the polymer products by either using an aqueous monomer solution of high concentration, or by using the aqueous monomer solution of low concentration and dehydrating by azeotropic distillation If the dispersing medium containing a compound having a boiling point of 1500 C or higher, the polymers should be washed with a solvent having a 25 boiling point lower than 1500 C after separation of the dispersing medium Also, in the case when ethyl cellulose or hydroxyethyl cellulose is used as the dispersion stabilizer, the polymers should be washed with a solvent dissolving these cellulose derivatives, since the surface of the bead polymers separated becomes tacky upon directly drying them to remove the dispersing medium On the other hand, the 30 products obtained by using cellulose acetate butyrate as the dispersion stabilizer do not require washing; the coating of cellulose acetate butyrate remained on the surface of the bead polymers rather displays an effect preventing the products from adhering.

It will thus be apparent that by operating in accordance with the present invention 35 it is possible to carry out the polymerization of from 60 to 90 % by weight aqueous solutions containing the monomer of the formula I or a mixture of the I and other monomer in the drop dispersed state, since very stable dispersion systems can be formed by the combined use of the dispersion stabilizer and the dispersing medium without any operation, for example equalizing the specific density of the aqueous 40 monomer solution and the dispersing medium In this case, the dehydration operation may be significantly improved or eliminated Furthermore, preferred embodiments of the present invention provide solid bead polymers of uniform particle size and with good handling characteristics in a fairly simple manner in which the gelatinous products containing a large amount of water, which are formed by the polymerization, 45 are subjected to dehydration by the dispersing medium-water azeotropic distillation.

The invention will now be further described with reference to the following Examples.

Examples 1 to 12 and Comparative Examples 1 to 4:

2 g of a dispersion stabilizer shown in Table 1 was dissolved in 90 g of a 50 dispersing medium also shown in Table 1, and the solution was fed into a 200 ml four-necked separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene 29 7 g of 80 % aqueous solution of P-methacryloyloxyethyl trimethyl ammonium chloride and 0 3 g of 20 % aqueous solution of 2,2 '-azo-bis-2-amidinopropane hydrochloride 55 were fed into the dropping funnel After removing oxygen from the reaction vessel and the dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the vessel which was heated to WC while stirring at 100 r p m Then the reaction mixture was heated to 60 WC for 2 hours while stirring at from 110 to 150 r p m After cooling, the product was 60 filtered off and dried to remove the dispersing medium; thus a solid bead polymer free from very fine powder was obtained without the need for dehydration There was observed, in each case, no adhesion to the reaction vessel and the stirring blade.

The reduced viscosity of each of the products was measured at 25 C of 0 1 % in 1 N aqueous sodium chloride The results are given in Table 1.

TABLE 1

Ratio by Dispersing medium weight Example 1 Ethyl acetate 2 Toluene: Ethyl acetate 1/1 n Dispersion stabilizer Cellulose acetate Acetyl group 40 % by weight 2 Cellulose acetate butyrate Acetyl group 29 5 % by weight Butyryl group 17 % by weight Reduced viscosity of the product Asp/c Form of the product ( 0 1 % IN-Na CI, 25 C) Bead, containing a small amount of lumps Bead, uniform particle size 7.7 8.3 3 Toluene: Methoxy ethyl acetate 4 Xylene: Ethyl acetate Chlorobenzene: Ethyl acetate 6 Benzene Ethyl acetate 7 Toluene Butyl acetate 8 Toluene Methyl caproate 9 Chlorobenzene Ethyl acetate Toluene: Ethyl acetate 11 Chlorobenzene Ethyl acetate 12 Toluene: Ethyl acetate 1/1 1 '1 1/1 2/1 1/1 1/5 9/1 7/1 1/4 10/1 0.4 1/2 Cellulose acetate butyrate Acetyl group 13 % by weight Butyryl group 37 % by weight Cellulose acetate butyrate Acetyl group 6 % by weight Butyryl group 48 % by weight Sg has been used Cellulose acetate phthalate Ethylcellulose Ethoxy group 45 46 5 % by weight \ O 7.0 7.8 6.9 8.0 7.9 -i, 00 U I.^ 7.0 6.6 7.5 7.6 8.85 to TABLE 1 (Continued) Ratio by weight Dispersing medium n Diaspersion stabilizer Reduced viscosity of the product asp/c Form of the product ( 0 1 % 1 N-Na CI, 25 C) Example of comparison 1 Toluene None Lump 6 5 2 Chlorobenzene,, ,, 6 O 3 Toluene Sorbitan monolaurate,, 5 O 4 Chlorobenzene Sorbitan monooleate,, 5 8 Examples 13 to 32:

3 g of a dispersion stabilizer shown in Table 2 was dissolved in 100 g of dissolving medium also shown in Table 2 and the solution thus obtained was fed into a 200 cc four-necked separable flask equipped with a condenser (cooling tube), a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene 50 g of 80 % aqueous solution of P-methacryloyloxyethyl trimethyl ammonium chloride and lg of 10 % aqueous solution of 2,2 '-azo-bis-2amidinopropane hydrochloride were fed into the dropping funnel After removing oxygen from the reaction vessel and the dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the reaction vessel while stirring at 100 r p m Then, the reaction mixture was held in nitrogen atmosphere at 60 C for one hour while being stirred at 110-150 r p m After cooling, the product was filtered and dried to remove the dispersing medium; thus solid uniform grain bead form polymer free from fine powder was thus obtained without the need for dehydration In each case no adhesive to the reaction vessel and the stirring blade was observed during polymerization The results are as shown in Table 2.

00 1 ? l,o km) U)A C> TABLE 2

Dispersing medium Example 13 Toluene: Cyclohexanone 14 Toluene: Acetone Ratio by weight 1/2 3/1 n Dispersion stabilizer 1 Cellulose acetate acetyl group 9 4 % by weight 4 Cellulose acetate butyrate Acetyl group 29 5 % by weight Butyryl group 17 % by weight Reduced viscosity of the product a/sp/c Form of the product ( 0 1 %/N-Na CI 25 C) Bead, uniform particle size 5.9 9.4 Toluene: MEK 16 Xylene: Cyclohexanone 17 Chlorobenzene: Cyclohexanone 18 Toluene: Acetone 2/1 2/1 2/1 5/1 19 Chlorobenzene: Acetone 9/1 Toluene: MEK 4/1 21 Toluene: MIBK 3/1 22 Chlorobenzene: MIBK 9/1 23 Chlorobenzene: Cyclohexanone 19/1 24 Toluene: Acetophenone 3/1 Chlorobenzene: Methyl benzoate 3/1 26 Toluene: Diethyl phthalate 2/1 Cellulose acetate butyrate Acetyl group 13 % by weight Butyryl group 37 % by weight 8.7 7.6 6.9 9.5 o 00 t j 8.5 9.3 9.9 9.8 8.6 9.3 8.0 9.8 I-.

i-a i 1 1 1 1 1 TARI P 2 (Conntinuld) Ratio Reduced viscosity of by 'the product rsp/c Dispersing medium weight N Dispersion stabilizer Form of the product ( 0 1 %/N-Na Cl 25 C) Example 27 Chlorobenzene: Diethyl phthalate 3/1 4 Cellulose acetate butyrate Bead, uniform particle 9 8 Acetyl group 13 % by weight size Butyryl group 37 % by weight 28 Toluene 1,2-Dichloroethane 1/2 1,,,, 8 9 29 Xylene 1,2-Dichloroethane 1/2 1,,,, 9/1 Chlorobenzene: 1,2-Dichloro 1/2 1,,,, 8 9 ethane 31 Toluene Pentachloroethane 1/2 1 7 5 32 Toluene 1,2-Dichloropropane 1/4 1/2 7 2 Example 33.

300 g of ethylene acetate was fed into a 1 % separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of stainless steel After 12 g of cellulose acetate butyrate (Acetyl group; 29 5 % 5 by weight and butyryl group; 17 % by weight) was added and dissolved in the flask, 300 g of toluene was added and stirred until uniformity of solution was ensured.

g of 80 % aqueous solution of,f-methacryloyloxyethyl trimethyl ammonium chloride and 2 g of 20 % aqueous solution of 2,2 '-azo-bis-2amidinopropane hydrochloride were fed into the dropping funnel After removing oxygen from the reaction vessel 10 and the dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the reaction vessel while being stirred at 100 r p m Then the reaction mixture was heated to 60 C for two hours for polymerization while being stirred at 150 r p m After cooling, the product was filtered, washed with ethyl acetate and dried to obtain 200 2 g of glass bead-like 15 polymer In each case no adhesion to the glass reaction vessel and the stirring blade was observed The grain size of 97 % of the product product was outside the range of from 100 mesh to 20 mesh and very little fine powder was produced Reduced viscosity ( 0 1 % solution at 25 C) of product of 0 1 % in 1 N-Na CI solution of salt (lsp/c) was 11 9 20 Instead of using jf-methacryloyloxyethyl trimethyl ammonium chloride (DMAEMA MC) as in Example 33, various polymerizing processes were carried out in a manner similar to that used in Example 33 but using 200 g of the various aqueous monomer solution shown in Table 3 The results were as follows:

_ Ui TABLE 3

Concentration of monomer (weight %) Form of product Reduced viscosity of product (rsp/c O 1 % 1 N Na CI 25 C) Example 34 DMAEMA'MC ( 60 mole % 1) 70 % Bead, uniform particle size 7 8 AAM ( 40 mole 6 %) DMAEMA'MS 80 %,, 2 3 36 DMAEMA MS ( 10 mole %) 50 %,, 8 1 AAM ( 90 mole %) Uniform particle size 37 DMAEMA 1 /2 H 2504 80 %,, 6 9 38 DMAEA EB 80 %,, 1 9 AAM: Acrylamid DMAEMA MC: /8-methacryloyloxyethyl trimethyl ammonium chloride DMAEMAMS: /-methacryloyloxyethyl trimethyl ammonium methyl sulfate DMAEMA 1/2 H 2 SO 4: Neutralized salt produced by adding sulfuric acid to dimethylaminoethylmethacrylate.

PH value of 1 % aqueous solution was 6 DMAEA EB: /3-acryloyloxyethyl dimethylethyl ammonium bromide 2 g of 20 % aqueous solution of ammonium persulfate was used as the polymerization initiator Monomer -Io W Examples 39 to 41.

33.3 g of a diethylphthalate and 66 7 g of toluene were introduced into a 200 cc four-necked separable flask equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene and, then, 3 g of cellulose acetate butyrate (acetyl group; 13 % by weight and butyryl group; 37 %o by weight) was added thereto and dissolved therein 50 g of aqueous monomer solution shown in Table 4 and the specified quantity of 10 % aqueous solution of polymerization initiator were added to the dropping funnel and oxygen was removed by introducing nitrogen gas into the reaction vessel and the dropping funnel Then, the aqueous monomer solution in the dropping funnel was introduced into the reaction vessel while stirring at 100 r p m Then, the reaction mixture was heated while stirring at 110-150 r p m and kept at 60 C for one hour in the nitrogen atmosphere.

The results are shown in Table 4.

TABLE 4

Concentration of monomer (weight o%) Monomer Polymerization initiator Polymerization initiator Quantity added (Weight % of initiator in aqueous monomer solution) Reduced viscosity of product i/sp/c Form of product 0 1 % 1 N-Na CI 25 C) Example 39 DMAEMA'MC ( 60 mole %) 80 ABA 2 HC 1 0 2 Bead, uniform 11 5 AAM ( 40 mole %) particle size DMAEMA-MC ( 10 mole %) 40,,, 10 8 AAM ( 90 mole %) 41 DMAEMA-MS 85, 2 4 ABA 2 HCI: 2,2 '-Azo-bis-2-amidinopropane hydrochloride Examples 42 to 47.

The aqueous monomer solution shown in Table 5 was polymerized in the same manner as in Examples 39 to 41, except using 20 g of methylethyl ketone and 80 g of toluene instead of 33 3 g of diethyl phthalate and 66 7 g of toluene The results are as shown in Table 5.

o 00 Ji Uia tao CL TABLE 5

Polymerization initiator Concentration Quantity added of aqueous (Weight % of initiator Reduced viscosity monomer solution Polymerization in aqueous monomer of product r/sp/c Monomer (Weight %) initiator solution) Form of product ( 0 1 % 1 N-Na CI 25 C) Example 42 DMAEMA-MC 80 APS 0 2 Bead, uniform 5 3 particle size 43 DMAEMA'MC ( 60 mole % 1) 80 ABA-2 HCI O 2,, 8 9 AAM ( 40 mole 1 %) 44 DMAEMA'MC ( 10 mole % 1) 40 ABA-2 HC 1 O 05,, 8 0 AAM ( 90 mole %) DMAEMA'MS 85 ABA 2 HC 1 0 2,, 2 0 46 DMAEMA'1/2 H 2 SO 4 ( 60 mole %) 70 ABA 2 HC 1 0 2 9 3 AAM ( 40 mole %) 47 DEAEA'EB ( 10 mole %) 40 ABA'2 HC 1 O 05, 8 0 AAM ( 90 mole %) DEAEA EB: 3-Acryloyloxyethyltriethylammonium bromide APS: Ammonium persulfate Examples 48 to 53.

65.7 g of 1 2-dichloroethane and 33 3 g of xylene were introduced into a 200 cc four-necked separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene and, 5 then, 3 g of cellulose acetate butyrate (acetyl group; 13 % by weight and butyryl group; 37 % by weight) was added thereto Designated amount of monomer solution and 10 % aqueous solution of polymerization initiator were added to the dropping funnel and oxygen was removed by introducing nitrogen gas into the reaction vessel and the dropping funnel Then,' the aqueous monomer solution in the dropping 10 funnel was introduced into the reaction vessel while stirring at 100 r p m Then, the reaction mixture was heated while stirring at 110-150 r p m and kept at 60 C for one hour in the nitrogen atmosphere The results are as shown in Table 6.

TABLE 6

Concentration of aqueous monomer solution (weight %) Polymerization initiator Quantity of added polymerization initiator (Weight % of initiator in aqueous monomer solution) oReduced viscosity of product /sp/c Form of product ( 0 1 % 1 N-Na Cl 25 C) Example 48 DMAEMA'MC 49 DMAEMA-MC ( 60 mole %) AAM ( 40 mole %) DMAEMA-MC ( 10 mole %) AAM ( 90 mole o%) % % % APS ABA 2 H Cl ABA 2 H Cl 0.2 % 0.2 % 0.05 % Bead, uniform particle size 10.1 Hydrated substance uniform particle size 11.2 51 DMAEMA'MS % 52 DMAEMA 1/2 H 2 SO 4 ( 60 mole %) 70 % AAM ( 40 mole %) 53 DEAEA'EB ( 10 mole %) AAM ( 90 mole %) % ABA 2 H Cl ABA 2 HC 1 ABA 2 HC 1 0.2 % 0.2 % 0.05 % Bead, uniform particle size , Hydrated substance uniform particle size Examples 54 to 63.

3 g of dispersion stabilizer shown in Table 7 was dissolved in 100 g of dispersion medium also shown in Table 7 and the solution was fed into a 200 cc fournecked separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene 50 g of 80 % aqueous solution of p-methacryloyloxyethyl trimethylammonium chloride and lg of % aqueous solution of 2,2 '-azo-bis-2-amidinopropane hydrochloride were fed into the dropping funnel After removing oxygen from the reaction vessel and the dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the vessel under stirring at 100 r p m Then, the reaction mixture was heated to 60 C for one hour while stirring at 200 to 250 r p m After cooling, the product was filtered and washed with ethyl acetate and ethyl acetate was evaporated; a bead form polymer free from fine powder was thus obtained without the need for dehydration In each case no adhesion to the reaction vessel and stirring blade was observed during polymerization The results are shown in Table 7.

2.4 9.7 9.2 Monomer k-^ o 00 b) -.

TABLE 7

Dispersing medium Weight ratio Dispersion stabilizer Form of product Reduced viscosity of product -/sp/c ( 0.4 % 1 N-Na CI 25 C) Cyclohexane/Toluene 3/1 Ethyl cellulose ethoxy group ( 48, 0-49 5 % by weight) Bead, uniform particle size Cyclohexane/Toluene 56 Cyxlohexane /Chlorobenzene 57 Cyclohexane/Ethyl acetate 58 Cyclohexane/Diethyl phthalate 59 Cyclohexane/Methyl ethyl ketone Cyclohexane/Acetophenone 61 Cyclohexane/1 2-Dichloroethane 62 Cyclohexane/Di-n-butyl ether 63 Cyclohexane/n-butanol 3/1 3/1 3/1 3/1 3/1 3/1 3/1 10/1 10/1 Examples 64 to 68 and Comparative Example 5.

After the dispersion stabilizer was dissolved in the dispersing medium at 70 C in conformity with the method employed in Examples 54 to 63, an aqueous monomer solution was added thereinto while heating the solution at 60 C Then, the solution was polymerized under the same conditions described in Examples 54 to 63 The results are as shown in Table 8.

Example 54

7.2 7 1 7.3 7.8 8.1 7.0 00 oo is J uia 7.9 6.3 8.0 7.5 o 00 TABLE 8

Dispersing medium Dispersion stabilizer Form of product Reduced viscosity of product 7/sp/c ( O 1 % 1 N-Na CI 25 C) Example 64 Cyclohexane Ethylcellulose (Ethoxy group 47 5 49 % by weight) Bead, uniform particle size Cyclohexane Ethylcellulo S e (Ethoxy group 4849.5 % by weight) 66 Methylcyclohexane 67 Cyclooctane 68 Decalin Comparative example 5 Cyclohexane Polyoxyethylenenonylphenylether Lump form polymer Examples 69 to 74.

g of cyclohexane and 25 g of chlorobenzene were introduced into 200 cc fournecked separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene and 3 g of ethylcellulose (Ethoxy group 48 0-49 5 % by weight) was added to the solution and dissolved 50 g of aqueous monomer solution shown in Table 9 and the specific quantity of 10 % aqueous solution of polymerization initiator were fed into the dropping funnel After removing oxygen from the reaction vessel and the dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the reaction vessel while stirring at 100 r p m Then, the reaction mixture was heated to 60 C for one hour while stirring at 200 to 250 r.p m in the nitrogen atmosphere The results are shown in Table 9.

7.6 7.7 6.9 7.2 7.5 6.0 U.#i L^ )e TABLE 9

Concentration of monomer Polymerization initiator (Weight %) Polymerization initiator Quantity added (Weight % of initiator in aqueous monomer solution) Form of product Reduced viscosity of product r/sp/c ( 0.1 % IN-Na CI 25 C) Example 69 DMAEMA MC DMAEMA MC AAM ( 60 mole %) ( 40 mole 1 %) 71 DMAEMA MC ( 10 mole 1 %) AAM ( 90 mole %) 72 DMAEMA MS % % % % 73 DMAEMA 1/2 H 2, SO 4 ( 60 mole %) 70 % AAM ( 40 mole %) 74 DEAEA EB ( 10 mole %) % APS ABA 2 H Cl ABA 2 HC 1 ABA 2 H Cl ABA'2 H Cl ABA 2 H Cl 0.2 % Bead, uniform particle size 022 % 0.05 % 0.2 % 0.2 % 0.05 % Examples 75 to 89.

g of the dispersing medium shown in Table 10 and 3 g of ethylhydroxy ethyl cellulose were introduced into a 200 cc four-necked separable flask which is equipped with a condenser, a nitrogen introducing tube, a dropping funnel and a stirring blade made of polytetrafluoroethylene While removing oxygen by introducing nitrogen, the solution was heated to 60 C, 50 g of 80 %,-methacryloyloxyethyl trimethylammonium chloride and lg of 10 % aqueous solution of 2,2 '-azo-bis-2amidinopropane hydrochloride were fed into the dropping funnel and nitrogen gas was introduced thereinto.

Then, the mixture was dropped into the aqueous monomer solution in the dropping funnel while being stirred at 200 to 250 r p m and heated at 60 C for one hour in the nitrogen atmosphere The results are shown in Table 10.

4.4 8.7 10.4 2.4 9.7 ui' 7.5 1 Reduced viscosity hi of product r/sp/c Example Dispersing medium Mixing rate Dispersion stabilizer Form of product ( 0 1 % 1 N-Na CI, 25 C) n-Hexane/Ethyl acetate 20/1 Ethylhydroxyethyl -Bead, uniform 9 7 cellulose particle size 76 n-Hexane/Acetone 20/1,,,, 9 5 77 n-Hexane / 1, 1, 2-Trichloroethane 20/1 9 6 78 n-Hexane/n-dibutylether 20/1, 9 1 79 n-Hexane/Toluene 20 /1 8 1 n-Hexane/Chlorobenzene 20/1 9 7 81 n-Hexane/Cyclohexane 1/4,,, 8 9 82 n-Heptane/Cyclohexane 1/4 9 8 o t JJ 83 n-Heptane/Cyclohexane 1/1 93, 84 n-Heptane/Methylcyclohexane 1/4, 9 4 n-Heptane/Cyclooctane 1/4, 9 7 86 n-Heptane /Decalin 1/4, 9 3 87 Tetradecene/Cyclohexane 1/3,,, 9 7 88 Kerosene/Cyclohexane 1/4,,,, 6 1 89 Liquid paraffin/Cyclohexane 1/2,,,, 9 8 Examples 90 to 93.

Ethylhydroxyethyl cellulose was dissolved in the dispersing medium shown in Table 11 by heating and, then, the solution was polymerized under the same conditions described in Examples 75 to 89, except the polyrmerizing temperatures shown in 5 Table 11 were used The results are shown in Table 11 o TARIF P 10} TABLE 11

Dissolving temperature Reduced viscosity of Polymerizing of product A/sp/c Example dispersing medium temperature Form of product ( 01 % in 1 N-Na CI 25 C) n-Hexane 65 C 60 C Bead, uniform 8 8 particle size 91 n-Heptane 70 C 60 C,, 9 1 92 n-Octane 90 C 70 C,, 7 1 93 Kerosene 70 oc 60 C,, 5 2 Examples 94 to 99 g of ethyl acetate was introduced into a 11 separable flask equipped with a condenser, a nitrogen introducing tube, a dropping funnel and an anchor type stirring blade made of stainless steel 7 2 g of cellulose acetate butyrate (Acetyl 5 group; 29 5 % by weight and Butyryl group; 37 % by weight) was added and dissolved, after which 180 g of toluene was added to the solution and stirred until a uniform mixture was obtained 240 g of aqueous monomer solution shown in Table 12 and 2 4 g of 10 % solution of 2,2 '-azo-bis-2-amidinopropane hydrochloride were fed into the dropping funnel After removing oxygen from the reaction vessel and the 10 dropping funnel by introducing nitrogen thereinto, the aqueous monomer solution in the dropping funnel was introduced into the vessel while being stirred at 100-120 r.p m Then, the reaction mixture was heated while being stirred at 120150 r p m.

and held at 50 C for 3 hours while being stirred in the nitrogen atmosphere Then, the flow of nitrogen was stopped, the condenser (cooling tube) was disconnected and 15 an azeotropic distillation device was provided The temperature was kept at 9093 C and dehydrated by the azeotropic distillation After most of water was distillated, the product was cooled and the dispersing medium removed; a uniform solid bead polymer was thus obtained During the azeotropic distillation, little adhesion of the polymer particles to each other or to the reaction vessel was observed 20 More than 95 % (by weight) of particle size was 0 1 mm to 1 0 mm and the yield was more than 94 % The results are shown in Table 12.

t >O Aqueous monomer solution used TABLE 12

Water content in polymer (Weight %) Before dehydration After dehydration Form of product Reduced viscosity of product asp/c ( 0.1 % 1 N-Na CI 25 C) 94 DMAEMA MC AAM ( 60 % aqueous DMAEMA MC AAM ( 60 % aqueous 96 DMAEMA MC AAM ( 40 % aqueous 97 DMAEMA MS AAM ( 40 % aqueous ( 80 mole 1 %) ( 20 mole O %) solution) ( 40 mole %) ( 60 mole 1 %) solution) ( 10 mole %) ( 90 mole %) solution) ( 10 mole o%) ( 90 mole /%) solution) 98 DMAEMA 1/2 H 2 SO 4 ( 10 mole %) AAM ( 90 m 61 e %) ( 40 % aqueous solution) 99 DEAEA EB ( 10 mole '%) AAM ( 90 mole '%) ( 40 % aqueous solution) Dispersing medium % % % Bead, uniform particle size 16 % % 13 % % 12 % % 13 % % 11 % Toluene/Ethyl acetate lWeight ratiol Weight ratio X = 1/1 N = 2Examples 100 to 101 and Comparative Examples 6 to 7.

3.9 of dispersing agent shown in Table 13 was dissolved in 100 g of dispersing medium also shown in Table 13, and the solution thus obtained was fed into a 200 cc separable flask equipped with a condenser, a thermometer, a nitrogen introducing tube, a dropping funnel and stirring blade made of polytetrafluoroethylene With the use of 50 g of 40 % aqueous monomer solution, a mixture of 10 mol% of DMAEMA and 90 mol% of AAM, the polymerization was carried out in a manner similar to that used in Examples 94 to 99.

The results are shown in Table 13.

Example t N 6.1 8.2 15.0 9.1 00 %o, t.i ui 8.6 10.1 W, W.

Examples 102 to 104.

Polymerization was performed at 60 C by using the dispersing medium and the stabilizer shown in Table 13 Other conditions were similar to those in Examples 94 to 99.

The results are shown in Table 13.

TABLE 13

Dispersing medium Weight ratio n Dispersing agent Form of product Reduced viscosity of product asp/c ( 0.1 % 1 N-Na CI 25 C) Toluene/Diethyl phthalate Xylene/1,2 Dichloroethane Cy clohexane 2/1 1/2 3 Cellulose acetate butyrate Acetyl group 13 % by weight Butyryl group 17 % by weight Bead, uniform particle size Ethyl cellulose (Ethoxy group 47 5 49 weight l%) Cyclohexane Cyclohexane/Liquid paraffin Ethyl cellulose (Ethoxy group 48 49 5 weight %) 3/1 Cy clohexane Ethylhydroxyethyl cellulose Polyoxyethylene Nonylphenylether Lump form polymer Sorbitanmonolaurate Example so tao 101 102 103 104 Comparative example 6

10.8 11.2 00 wi ti ui 9.2 9.8 8.7 9.5 7 Toluene 7.1 1,583,235 In the above Examples, the following were used as cellulose ester ether.

Cellulose acetate Eastman Kodak Chemicals Cellulose acetate butyrate Eastman Kodak Chemicals and cellulose Acetyl content 39 4 wt% CAB 171 Butyryl 17 wt% CAB 381 Butyryl 37 wt% CAB 500 Butyryl 48 wt% acetyl 29 5 wt% acetyl 13 wt% acetyl 6 wt% Cellulose acetate phthalate Wako Pure Chemical Ethyl Cellulose Doe Chemical Corporation Hercules Incorporation Ethylhydroxyethyl Cellulose Hercules Incorporation CAP-wako ETHOCEL MED Ethoxy 45 46 5 wt% ETHOCEL STD Ethoxy 48 49 5 wt% Ethyl Cellulose N Type Ethoxy 47 5 49 0 wt% EHEC Low Viscosity: 25 to 35 centipoise ( 25 C, 5 % in a solvent mixture of 80 parts by weight toluene and 20 parts ethanol) ETHOCEL is a Registered Trade Mark.

The following were used as the raw monomer and initiator:

Name of raw material Manufacturer Trade name AAM Mitsubishi Kasei Kogyo DMAEMA MC, Mitsubishi Rayon Acrylester DM-MC (Dimethylaminoethylmethacrylate) DMAEMA Mitsubishi Rayon Acrylester DM DMAEMA'MS, DMAEMA-1/2 H 2 SO 4, used in the examples were obtained by reacting DMAEMA with dimethyl sulfate and neutralizing with sulfuric acid.

DMAEA and DEAEA NIPPON NYUKAZAI CO, LTD.

DMAEA EB and DEAEA-EB were obtained by reacting DMAEA and DEAEA with ethyl bromide.

ABA-2 HCI Wako Pure Chemical V-50

Claims (1)

1. WHAT WE CLAIM IS:-

   1 A process for preparing a water-soluble bead polymer by dispersing drops of an aqueous solution of water-soluble vinyl monomer in a dispersing medium in the presence of a dispersion stabilizer, and polymerizing the monomer, wherein the monomer is selected from: 5 (A) a compound of the general formula I R' Rx CH, = C C O Y N R' Xe 3 '11 1 ' 0 R (I) wherein R 1 is hydrogen or methyl, R 2 and R' may be the same or different and each is linear or branched alkyl of from 1 to 4 carbon atoms, R 4 is hydrogen, linear or branched alkyl of from 1 to 8 carbon atoms, hydroxy alkyl of from 1 to 4 carbon 10 atoms, or benzyl, Y is alkylene or hydroxyalkylene each of from 2 to 4 carbon atoms, and X is an anion; and (B) a mixture of the compound of the formula I and a water-soluble vinyl monomer copolymerizable with the compound (I); and a cellulose ester or a cellulose ether insoluble in water but soluble in the dispersing medium is used as the dispersion 15 stabilizer.

   2 A process according to claim 1 wherein the concentration of the monomer (A) or mixture of monomer (B) in the aqueous solution is from 10 to 90 % by weight, based on the total of monomer and water.

   3 A process according to claim 2, wherein the amount of the compound I in 20 the monomer mixture (B) is from 50 to 100 mole%, and the concentration of the monomer mixture (B) in the aqueous solution is from 60 to 90 % by weight, based on the total of monomer and water.

   4 A process according to claim 2, wherein the amount of the compound I in the monomer mixture (B) is in a range of from 5 mole% to 50 mole%, and the 25 concentration of the monomer mixture (B) in the aqueous solution is in a range of from 10 % to 60 %, based on the total weight of monomer and water, and including the further step of subjecting the resultant water-containing product to an azeotropic distillation thereby to remove water contained in the polymer.

   5 A process according to any one of claims 1 to 4, wherein the dispersion 30 stabilizer is at least one compound selected from a group comprising cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, cellulose acetate phthalate, ethyl cellulose, ethyl hydroxyethyl cellulose and benzyl cellulose.

   6 A process according to any one of claims 1 to 5 wherein the dispersion stabilizer is at least one compound selected from a group consisting of cellulose 35 acetate butyrate, cellulose acetate, ethyl cellulose and ethyl hydroxyethyl cellulose.

   7 A process according to claim 6, wherein the dispersion stabilizer is cellulose acetate butyrate and/or ethyl cellulose containing from 43 to 46 % by weight of ethoxy groups.

   8 A process according to claim 7, wherein the dispersing medium is a mixture 40 of:

   (I) at least one compound selected from a group comprising esters, ketones and alkyl halides; and (II) an aromatic hydrocarbon and/or a halogenated aromatic hydrocarbon.

   9 A process according to claim 8, wherein the dispersion stabilizer is cellulose 45 acetate butyrate and the dispersion medium is a mixture of at least one compound selected from a group comprising esters of aliphatic carboxylic acids of from 1 to 8 carbon atoms with alkanols or alkoxy alkanols each of from 1 to 8 carbon atoms, and an aromatic hydrocarbon and/or a halogenated aromatic hydrocarbon.

   10 A process according to claim 6, wherein the dispersion stabilizer is ethyl 50 hydroxyethyl cellulose.

   11 A process according to claim 10, wherein the dispersing medium is a saturated aliphatic hydrocarbon or a mixture of a saturated aliphatic hydrocarbon and another compound.

   12 A process according to claim 11, wherein the saturated aliphatic hydrocarbon 55 is a compound having a boiling point in the range of from 35 to 4001 C.

   13 A process according to claim 12, wherein the saturated aliphatic hydrocarbon is a compound having a boiling point in the range of from 35 to 180 TC.

   1,583,235 26 1,583,235 26 14 A process according to claim 13, wherein the said saturated aliphatic hydrocarbon is at least one compound selected from a group comprising n-hexane, n-heptane and n-octane.

   A process according to claim 6, wherein the dispersion stabilizer is ethyl cellulose containing from 47 to 50 % by weight of ethoxy groups 5 16 A process according to claim 15, wherein the dispersing medium is a cycloaliphatic hydrocarbon or a mixture of a cycloaliphatic hydrocarbon and another compound.

   17 A process according to claim 16, wherein the cycloaliphatic hydrocarbon is at least one hydrocarbon selected from hydrocarbons of from 5 to 10 carbon atoms 10 18 A process according to claim 17, wherein the cycloaliphatic hydrocarbon is at least one compound selected from a group consisting of cyclohexane, methyl cyclohexane, cyclooctane and decaline.

   19 A process according to claim 18, wherein the cycloaliphatic hydrocarbon is cyclohexane 15 A process according to any one of claims 1 to 19, wherein the compound of the formula I is at least one compound selected from a group consisting of salts of dialkylaminoethyl methacrylates and mineral acids, and quaternary ammonium salts of dialkylaminoethyl methacrylates with alkyl halides or dialkyl sulfates.

   21 A process according to claim 20, wherein the compound of the formula I is 20 B-methacryloyloxyethyl trimethylammonium chloride.

   22 A process according to claim 1 substantially as described with reference to any one of the Examples herein.

   23 A polymer produced by the process of any one of the preceding claims.

   TREGEAR, THIEMANN & BLEACH, Chartered Patent Agents, Enterprise House, Isambard Brunel Road, Portsmouth, PO 1 2 AN, and 49/51, Bedford Row, London, WC 1 V 6 RL.

   Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1981.

   Published by the Patent Office, 25 Southampton Buildings, London, WC 2 A l AY, from which copies may be obtained.